SPIROCHa;TOSIS OP SUDANESE FOWLS 93 



In tho second place, therefore, attention is directed to the series of observations 

 conducted on the lines of Leishman's' suggestive work on the peculiar chromatin granules 

 which he described as occurring in the tissues of 0. moubata fed on blood containing 

 Sp. duttoni. This work appeared after I had proved that A. persicus was a carrier of 

 the Sudan spirochsetosis of fowls, and it led me to investigate the matter with a view to 

 finding if the Sudan spirochsete underwent similar changes. Such I speedily found to be 

 the case, and, so far as time permitted, I have endeavoured to follow out Leishman's methods 

 of investigation. It has not, however, been possible to obtain as much leisure as I could 

 have wished. Still the following results have been obtained. 



(i) Ticks (A. peisicus), either as larvae, nymphs, or adults, fed on chicks with acute 

 spirochastosis, exhibit peculiar chromatin granules. 



I have found these in the ovaries, eggs, oviducts, alimentary diverticula and salivary ■■ Granules" in 

 glands of the ticks, but more especially and in greatest number in the Malpighian tubes. -"'•/"•"Vw 

 Sir W. B. Leishman kindly examined my earlier preparations and assured me that the 

 granules, save in some minor particulars, are identical with those found by him. 



In carrying out experiments to illustrate this point my difficulty has been to find ticks 

 free of these granules. Spirochsetosis is so common and widespread in Khartoum that 

 ticks without these granules in some portion of their tissues are the exception. Again, as 

 Leishman points out both in his first- and second^ papers, " conservative surgery in the 

 case of a tick is unfortunately impossible," and hence "whatever conclusion one arrives at 

 as to the condition of a given batch or brood of ticks, must be founded on the examination 

 of a sample of such batch. However large the sample, and there are obvious limits to this 

 where it is desired to follow up the course of subsequent events in such a batch, any 

 conclusion is open to the objection that a diiferent condition existed in a member of 

 the group which was allowed to survive." It is, however, possible, without killing a 

 tick, to obtain coelemic fluid by amputating a leg, while the contents of the alimentary 

 diverticula can be obtained by snicking the edge of the body. The tiny wound, as 

 a rule, heals rapidly. I fear I was unable, through sheer lack of time, to make my samples 

 as large as Leishman's, but I did my best, and in this and other work of a like nature 

 I think my controls have been sufficient, for, like Leishman, I have examined a great 

 many ticks in all stages of their development. For the reason above stated it is not 

 easy to say how long a time elapses between the ingestion of spirochsetal blood and the 

 appearance of the granules in the place where they are most easily and constantly 

 demonstrated, the Malpighian tubes (Plate IV., fig. 1). We have seen (page 92) that 

 the spirochsetes themselves do not appear to persist in the tick for a longer period 

 than nine days under ordinary laboratory conditions. 



I have found granules within two days of the date of feeding, but cannot be sure that 

 they had not been present before. Until one obtains, by breeding or otherwise, a plentiful 

 supply of granule-free ticks this question cannot be settled. 



As regards the granules themselves, the best idea of their structure and arrangement Tendency of 

 will be obtained from the coloured drawing (Plate III., fig. 1), where they are shown both 'he grannies 



to form 



in the tissues and lying free. In both situations the tendency to form clumps is very ■■clumps" 

 marked. The individual granules are small, usuallj- coecal-shaped, though frequently 

 irregular in outline and, not rai-ely, appearing like small bacilli. They are so minute that 



' Leishman, W. B. (February, 1909), " Prelimiuary Note on Experiments in Connection with the 

 Transmission of Tick Fevers." Journal uf tin- Rmjal Army Medical Corps, Vol. 12, No. 2. 



- Loc. cit. 



■' Leishman, W. B. (.lanuarv, 1910), " Observations on the Slechanism of Infection in Tick Fever and 

 on the Hereditary Transmission of Hpirochieta Duttoni in the Tick." Transactions of the Society of Tropical 

 Medicine and Hu'jiene, Vol. 3, No. .3. 



